Burglar alarm



M. A. WEST BURGLAR ALARM Aug. 21, 1928.

Filed March 28, 1927 4 TTUR NE:

Patented Aug. 21, 1928.

UNITED STATES V MAXWELL A. wnsr, or PORTLAND, onneon.

nUnGLAR ALARM.

Application filed March as, 1927. Serial N5. 178,861.

This invention relates generally to devices v for protection a ainst burglary, and particularly to a special formof burglar alarm.

' The main object of this invention is to provide an exceedinglysimple and efficient burgla-r alarm which will be easy to manufacture and not readily put out of commission.

The second object is to produce a burglar alarm entirely independent of electrically operated mechanisms or spring motor devices.

The third object is to so construct the device that it can be set by aperson in a room before or after a door is closed, but once the door is closed a subsequent opening thereof will sound the alarm.

These, and other objects, will become more apparent from the specification following as illustrated in the accompanying drawing, in which:

Figure 1 is a plan of the device of which Figure 2 is a side elevation and Figure 3 a perspective view of a doorshowing one way in which the alarm can be set. Figure 4 is a horizontal section taken along the line 44 in Figure 3 showing the door about to be closed in full lines and just coming in contact with the device in dotted lines. Figure 5 is a View similar to Figure 4 but showing the alarm moved out of the way by the door. Figure 6 shows the door closed and the alarm in the position of rest. Figure 7 is an en larged perspective view of the preferred form of latch member employed in this device.

Similar numbers of reference refer to similar parts throughout the several views.

Referring in detail to the drawing, the device itself consists of a resilient member 10 having one end 11 sharpened to form a point and having attached to its opposite end 12 a bell 13. i

The manner of attaching the bell to the end 12 is unimportant and will depend upon the type of bell employed and other factors. In this case it is shown as a riveted connection in which the end 12 passes between the lugs 14 of the bell 13 and is secured by the rivet 15.

Near the middle of the flexible member 10 is secured a latch member 16 whose side 17 is toward the bell and whose face 18 is toward the point 11. The face 18 is preferably slight 1y undercut, as indicated, and the latch 16 is attached to the member 10 by means of the rivets 19, or in any other convenient manner.

The latch 16 may be made of rubber for the purpose of securing better frictional engagement with the door 20 or it may be made of Y latches.

other material and provided with a friction face which will not marthe door.

In the form shown in Figures 1 and 2 the resilient member 21 itself is bent to form the faces 22 and 23, the latter of which is provided with a rubber cover 24 which engages the door 20 when it isopened. A connecting tie 25 is placedacross the bent portion of the member 21 and secured thereto by means of rivets 26, or in any other convenient manner such as welding or otherwise joining the two elements.

In some cases it is preferable to slip a piece of rubber tubing over the portions 22 and 23 in order that no metallic contact shall be had with the door 20.

In operation the point 11 is thrust into the door jamb 27 or if a moulding stop is employed it is thrust in the crack between the moulding stop and the jamb itself. When the door is closed it engages the member 17 and pushes the device out of the way, but, after the door has passed the latch and approached the closed position shown in Figure 6, the latch 17 takes up its position behind the door 20 so that a subsequent opening of the door causes it to engage the face 18 and, owing to the undercut nature of the face 18, tovibrate the bell 13, and at the same time withdraw the point 11 from its place in the woodwork of the door casing causing it to .fall to the floor with a noise which will be sufficient to waken the soundest sleeper, if not to frighten away the most intrepid burglar.

It can be seen that the same condition will arise if the device is inserted on the top of the door instead of at its side. Also when used in connection with windows the movement up or down would cause it to fall with an accompanying loud noise.

I am aware that many modifications of this device could be constructed without departing from the spirit of this invention, for eX ample: Instead of the flat resilient member 10 a round wire could be employed and a conical latch could be used instead of the wedgeshaped form. Also many other types of bells could be used and shapes and varieties of I therefore do not intend to limit myself to this precise form of the device, but

I intend to cover all such forms thereof as fall naturally and fairly within the appended claims.

I claim:

1. A burglar alarm having, in combination,

a resilient pointed blade member adapted to he thrust into the woodwork of a door jamb between the door and its casing; a bell attached to said blade forming a handle member therefor; and a latch formedon one side of said blade having a sloping side facing said bell and a shouldered side facing the pointed on d of said blade, said latch having a soft face adapted to prevent the marring of said door and to increase the frictional engagement between said door and shoulder while said door is being opened until said bell is completely released from its support.

In a burglar alarm, the combination of a resilient blade having a bell mounted at one end thereof forming a handle for said blade and having the opposite end of said blade pointed, together with a latch means mounted on one side of said blade having one sloping side facing said bell and having one undercut shouldered side facing said pointed end, said undercut side having a resilient friction surface provided on its door-enga ing side.

3. In a burglar alarm, the com ination of a resilient blade member having one sharpened end and having a bell attached to its opposite end said blade having a latch positioned near the middle of its length said latch having a sloping side facing said bell, and a shouldered side facing its pointed end.

4. A burglar alarm consisting of a blade, a bell attached to said blade, and a stop formed on said blade adapted to engage a door in a manner that the opening movement of the door will release said blade from its support.

MAXWELL A. 

